Merge branch 'develop' into 'master'

Fix header changing

See merge request digital-twin/twinzo/tdevkit!38

SDK/Contracts/Data/AreaContract.cs

@@ -25,6 +25,7 @@ namespace SDK.Models
         public long Created { get; set; }
 
         public long Updated { get; set; }
+        public string ExternalId { get; set; }
     }
 
     public class PointContract

SDK/Contracts/Data/LayerContract.cs

@@ -25,5 +25,6 @@ namespace SDK.Contracts.Data
         public DeviceContract[] Devices { get; set; }
 
         public bool IsNoGo { get; set; }
+        public string ExternalId { get; set; }
     }
 }